<?php
/**
 * PHPExcel
 *
 * Copyright (c) 2006 - 2014 PHPExcel
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
 *
 * @category   PHPExcel
 * @package    PHPExcel_CachedObjectStorage
 * @copyright  Copyright (c) 2006 - 2014 PHPExcel (http://www.codeplex.com/PHPExcel)
 * @license    http://www.gnu.org/licenses/old-licenses/lgpl-2.1.txt	LGPL
 * @version    1.8.0, 2014-03-02
 */


/**
 * PHPExcel_CachedObjectStorage_MemoryGZip
 *
 * @category   PHPExcel
 * @package    PHPExcel_CachedObjectStorage
 * @copyright  Copyright (c) 2006 - 2014 PHPExcel (http://www.codeplex.com/PHPExcel)
 */
class PHPExcel_CachedObjectStorage_MemoryGZip extends PHPExcel_CachedObjectStorage_CacheBase implements PHPExcel_CachedObjectStorage_ICache
{

    /**
     * Store cell data in cache for the current cell object if it's "dirty",
     *     and the 'nullify' the current cell object
     *
     * @return    void
     * @throws    PHPExcel_Exception
     */
    protected function _storeData()
    {
        if ($this->_currentCellIsDirty && !empty($this->_currentObjectID)) {
            $this->_currentObject->detach();

            $this->_cellCache[$this->_currentObjectID] = gzdeflate(serialize($this->_currentObject));
            $this->_currentCellIsDirty = false;
        }
        $this->_currentObjectID = $this->_currentObject = null;
    }    //	function _storeData()


    /**
     * Add or Update a cell in cache identified by coordinate address
     *
     * @param    string $pCoord Coordinate address of the cell to update
     * @param    PHPExcel_Cell $cell Cell to update
     * @return    void
     * @throws    PHPExcel_Exception
     */
    public function addCacheData($pCoord, PHPExcel_Cell $cell)
    {
        if (($pCoord !== $this->_currentObjectID) && ($this->_currentObjectID !== null)) {
            $this->_storeData();
        }

        $this->_currentObjectID = $pCoord;
        $this->_currentObject = $cell;
        $this->_currentCellIsDirty = true;

        return $cell;
    }    //	function addCacheData()


    /**
     * Get cell at a specific coordinate
     *
     * @param    string $pCoord Coordinate of the cell
     * @throws    PHPExcel_Exception
     * @return    PHPExcel_Cell    Cell that was found, or null if not found
     */
    public function getCacheData($pCoord)
    {
        if ($pCoord === $this->_currentObjectID) {
            return $this->_currentObject;
        }
        $this->_storeData();

        //	Check if the entry that has been requested actually exists
        if (!isset($this->_cellCache[$pCoord])) {
            //	Return null if requested entry doesn't exist in cache
            return null;
        }

        //	Set current entry to the requested entry
        $this->_currentObjectID = $pCoord;
        $this->_currentObject = unserialize(gzinflate($this->_cellCache[$pCoord]));
        //    Re-attach this as the cell's parent
        $this->_currentObject->attach($this);

        //	Return requested entry
        return $this->_currentObject;
    }    //	function getCacheData()


    /**
     * Get a list of all cell addresses currently held in cache
     *
     * @return  array of string
     */
    public function getCellList()
    {
        if ($this->_currentObjectID !== null) {
            $this->_storeData();
        }

        return parent::getCellList();
    }


    /**
     * Clear the cell collection and disconnect from our parent
     *
     * @return    void
     */
    public function unsetWorksheetCells()
    {
        if (!is_null($this->_currentObject)) {
            $this->_currentObject->detach();
            $this->_currentObject = $this->_currentObjectID = null;
        }
        $this->_cellCache = array();

        //	detach ourself from the worksheet, so that it can then delete this object successfully
        $this->_parent = null;
    }    //	function unsetWorksheetCells()

}
